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Biomedical subjects

K Takada

Publications and source records attributed to K Takada.

At least 181 records · Page 10Linked to original sources
PubMed1999

Metabolic characterization of a tripeptide human immunodeficiency virus type 1 protease inhibitor, KNI-272, in rat liver microsomes.

KNI-272 is a tripeptide protease inhibitor for treating human immunodeficiency virus type 1 (HIV-1). In in vitro stability studies using rat tissue homogenates, KNI-272 concentrations in the liver, kidney, and brain decreased significantly with time. Moreover, in tissue distribution studies, KNI-272 distributed highly to the liver, kidney, and small intestine in vivo. From these results and reported physiological parameters such as the tissue volume and tissue blood flow rate, we considered the liver to be the main organ which takes part in the metabolic elimination of KNI-272. Then the hepatic metabolism of KNI-272 was more thoroughly investigated by using rat liver microsomes. KNI-272 was metabolized in the rat liver microsomes, and five metabolites were found. The initial metabolic rate constant (kmetabolism) tended to decrease when the KNI-272 concentration in microsomal suspensions increased. The calculated Michaelis-Menten constant (K(m)) and the maximum velocity of KNI-272 metabolism (Vmax), after correction for the unbound drug concentration, were 1.12 +/- 0.09 micrograms/ml (1.68 +/- 0.13 microM) and 0.372 +/- 0.008 microgram/mg of protein/min (0.558 +/- 0.012 nmol/mg of protein per min), respectively. The metabolic clearance (CLint,metabo), calculated as Vmax/K(m), was 0.332 ml/mg of protein per min. Moreover, by using selective cytochrome P-450 inhibitors and recombinant human CYP3A4 fractions, KNI-272 was determined to be metabolized mainly by the CYP3A isoform. In addition, ketoconazole, a representative CYP3A inhibitor, inhibited KNI-272 metabolism competitively, and the inhibition constant (Ki) was 4.32 microM.

Animals↗
PubMed1999

Oncogenic role of Epstein-Barr virus-encoded RNAs in Burkitt's lymphoma cell line Akata.

Our previous reports indicated that Epstein-Barr virus (EBV) contributes to the malignant phenotype and resistance to apoptosis in Burkitt's lymphoma (BL) cell line Akata (N. Shimizu, A. Tanabe-Tochikura, Y. Kuroiwa, and K. Takada, J. Virol. 68:6069-6073, 1994; J. Komano, M. Sugiura, and K. Takada, J. Virol. 72:9150-9156, 1998). Here we report that the EBV-encoded small RNAs (EBERs) are responsible for these phenotypes. Transfection of the EBER genes into EBV-negative Akata clones restored the capacity for growth in soft agar, tumorigenicity in SCID mice, resistance to apoptotic inducers, and upregulated expression of bcl-2 oncoprotein that were originally retained in parental EBV-positive Akata cells and lost in EBV-negative subclones. This is the first report which provides evidence that virus-encoded RNAs (EBERs) have oncogenic functions in BL cells.

Animals↗
PubMed1999

Epstein-Barr virus promotes epithelial cell growth in the absence of EBNA2 and LMP1 expression.

We attempted to infect primary gastric epithelia (PGE) with recombinant Epstein-Barr virus (EBV) carrying a selectable marker that made it possible to select EBV-infected cells. Cells dually positive for EBV-determined nuclear antigen (EBNA) and cytokeratin were detected in 3 of 21 primary cultures after 3 days of EBV inoculation. From one culture, EBV-infected cell clones were repeatedly obtained at a frequency of 3 to 5 cell clones per 10(6) cells. EBV-infected clones had enhanced population doubling and grew to attain a highly increased saturation density, together with acquisition of marked anchorage independence. The infected clones retained the ultrastructural morphology characteristic of gastric mucosal epithelium and have been growing stably for more than 18 months (corresponding to at least 300 generations) so far, in clear contrast to the parental PGE cells, which ceased growth after 60 generations. The p53 gene of the parental PGE cells was found to be overexpressed, perhaps thereby conferring the basal potential for long-term survival in vitro. Moreover, EBV infection accelerated, to a significant extent, the growth rate and agar clonability of NU-GC-3 cells, an established EBV-negative but EBV-susceptible human gastric carcinoma cell line. Both EBV-converted PGE and NU-GC-3 clones, like EBV-positive gastric carcinoma biopsy specimens, expressed a restricted set of EBV latent infection genes characterized by the absence of EBNA2 and latent membrane protein 1 (LMP1) expression. These results indicate that EBV infection causes a transformed phenotype on PGE in the setting of possible unregulated cell cycling and renders even established gastric carcinoma cells more malignant via a limited spectrum of viral latent-gene expression. This study may reflect an in vivo scenario illustrating multiphasic involvement of EBV in carcinogenesis of gastric or other epithelial cancers.

Cell Division↗
PubMed1999

The anamnestic neutralizing antibody response is critical for protection of mice from challenge following vaccination with a plasmid encoding the Japanese encephalitis virus premembrane and envelope genes.

For Japanese encephalitis (JE), we previously reported that recombinant vaccine-induced protection from disease does not prevent challenge virus replication in mice. Moreover, DNA vaccines for JE can provide protection from high challenge doses in the absence of detectable prechallenge neutralizing antibodies. In the present study, we evaluated the role of postchallenge immune responses in determining the outcome of JE virus infection, using mice immunized with a plasmid, pcDNA3JEME, encoding the JE virus premembrane (prM) and envelope (E) coding regions. In the first experiment, 10 mice were vaccinated once (five animals) or twice (remainder) with 100 micrograms of pcDNA3JEME. All of these mice showed low (6 of 10) or undetectable (4 of 10) levels of neutralizing antibodies. Interestingly, eight of these animals showed a rapid rise in neutralizing antibody following challenge with 10,000 50% lethal doses of JE virus and survived for 21 days, whereas only one of the two remaining animals survived. No unimmunized animals exhibited a rise of neutralizing antibody or survived challenge. Levels of JE virus-specific immunoglobulin M class antibodies were elevated following challenge in half of the unimmunized mice and in the single pcDNA3JEME-immunized mouse that died. In the second experiment, JE virus-specific primary cytotoxic T-lymphocyte (CTL) activity was detected in BALB/c mice immunized once with 100 micrograms of pcDNA3JEME 4 days after challenge, indicating a strong postchallenge recall of CTLs. In the third experiment, evaluation of induction of CTLs and antibody activity by plasmids containing portions of the prM/E cassette demonstrated that induction of CTL responses alone were not sufficient to prevent death. Finally, we showed that antibody obtained from pcDNA3JEME-immunized mice 4 days following challenge could partially protect recipient mice from lethal challenge. Taken together, these results indicate that neutralizing antibody produced following challenge provides the critical protective component in pcDNA3JEME-vaccinated mice.

Animals↗
PubMed1999

Behavior of jaw muscle spindle afferents during cortically induced rhythmic jaw movements in the anesthetized rabbit.

The regulation by muscle spindles of jaw-closing muscle activity during mastication was evaluated in anesthetized rabbits. Simultaneous records were made of the discharges of muscle spindle units in the mesencephalic trigeminal nucleus, masseter and digastric muscle activity (electromyogram [EMG]), and jaw-movement parameters during cortically induced rhythmic jaw movements. One of three test strips of polyurethane foam, each of a different hardness, was inserted between the opposing molars during the jaw movements. The induced rhythmic jaw movements were crescent shaped and were divided into three phases: jaw-opening, jaw-closing, and power. The firing rate of muscle spindle units during each phase increased after strip application, with a tendency for the spindle discharge to be continuous throughout the entire chewing cycle. However, although the firing rate did not change during the jaw-opening and jaw-closing phases when the strip hardness was altered, the firing rate during the power phase increased in a hardness-dependent manner. In addition, the integrated EMG activity, the duration of the masseteric bursts, and the minimum gape increased with strip hardness. Spindle discharge during the power phase correlated with jaw-closing muscle activity, implying that the change in jaw-closing muscle activity associated with strip hardness was caused by increased spindle discharge produced through insertion of a test strip. The increased firing rate during the other two phases may be involved in a long-latency spindle feedback. This could contribute to matching the spatiotemporal pattern of the central pattern generator to that of the moving jaw.

Afferent Pathways↗
PubMed1999

Influence of body composition on electrocardiographic identification of left ventricular hypertrophy in adolescents.

We investigated the influence of body composition on electrocardiographic (ECG) detection of left ventricular (LV) hypertrophy in 894 high-school students. The percent body fat and LV mass were estimated by bioelectrical impedance and echocardiography, respectively. There was no significant difference in LV mass among subjects classified according to the percent body fat. The cutoff ECG amplitudes (RV5 and SV1+RV5) for detection of LV hypertrophy (LV mass >/=90th percentile in both boys and girls) with 90% specificity were highest in the low-fat group and lowest in the high-fat group. When the effects of the percent body fat on ECG amplitudes were taken into account, the sensitivity of the ECG for detection of LV hypertrophy improved from 32.7 to 38.2% in boys; however, no improvement was observed in girls (from 33.3 to 30.6%). Evaluation of the percent body fat may improve the efficacy of ECG detection of LV hypertrophy in adolescent boys, but the usefulness of this method may be limited in girls.

Adipose Tissue↗
PubMed1999

Smoothness of human jaw movement during chewing.

Human limb movements are successfully modeled based on the assumption that the central nervous system controls the movements by maximizing movement smoothness. Movement smoothness is quantified by means of a time integral of squared jerk (jerk-cost), where jerk is defined as the rate of change in acceleration. This study was performed to investigate whether the control of human masticatory vertical jaw movements can also be explained by a minimum-jerk (maximum-smoothness) model. Based on the assumption that minimum-jerk models account for vertical jaw-opening and -closing movements during chewing, the actual time profile of the movement trajectory was simulated by the model. The simulated jerk-costs and peak velocities were compared with those obtained by actual measurements of jaw movements during chewing. Jerk-costs and peak velocities of the jaw movements during chewing were significantly correlated with those predicted by minimum-jerk models (P < 0.0001, r between 0.596 and 0.799). The minimum-jerk models predicted closing movement trajectories more accurately than opening movement trajectories (jaw opening, root-mean-square error = 1.19 mm; jaw closing, 0.52 mm, t = 4.375, P < 0.0001). The results indicated that the vertical jaw movement control during chewing was represented by the minimum-jerk control model and that the vertical jaw-closing movement is smoother than the opening movement during gum-chewing.

Adult↗
PubMed1999

A dissolution test for a pressure-controlled colon delivery capsule: rotating beads method.

The rotating beads method is a new in-vitro dissolution test proposed for drugs formulated as pressure-controlled colon delivery capsules (PCDCs). The apparatus consisted of a glass vessel (500 mL) containing 4-mm (i.d.) glass beads (5000, 10000 or 15000) and dissolution medium (0-067 M phosphate buffer, pH 7; 25, 50 or 100 mL) containing polyvinyl alcohol (PVA; 5, 10 or 20 w/v%) to simulate the viscosity of the colon. The vessel was rotated at 5, 10 or 25 rev min(-1) and the temperature was maintained at 37 degrees C. Fluorescein was used as a model drug to explore the optimized conditions under which differences in the drug dissolution rate are detected between colon delivery systems. Fluorescein was formulated in four types of colon delivery systems. One was a tablet coated with an enteric polymer, Eudragit S-100, and the other three were PCDCs prepared with different thicknesses of ethylcellulose coating membrane (type I, II, III). The dissolution behaviour of fluorescein from the PCDC formulation was significantly different from that of the Eudragit S-100-coated tablets, when the dissolution conditions were as follows: rotation speed, 10 rev min(-1); bead number, 10000; dissolution medium, 50mL with 10% PVA. This dissolution method was applied to acetaminophen sustained-release tablets and two other drugs having low solubility in the colon, tegafur and 5-aminosalicylic acid. Similarly, significant differences in the dissolution rates of drugs from the PCDC formulation and the enteric tablet were detected. There was good correlation between the in-vitro dissolution rates and in-vivo absorption rates using T50 (the time for half of the amount of drug to be released from the preparation) and Cmax/Tmax (enteric tablet) or Cmax/(Tmax-Ti) (PCDC), where Ti is the first appearance time in the systemic circulation. The rotating beads method is a valuable technique for evaluating the dissolution rate of drugs formulated in PCDC.

Administration, Rectal↗
PubMed1999

Regional and functional differences of 5-hydroxytryptamine-receptor subtypes in guinea pig stomach.

Functions and the presence of 5-hydroxytryptamine (5-HT) receptors in the fundus, corpus and antrum of the guinea pig stomach were examined by measuring contractile force and acetylcholine (ACh) release. Stimulation of the 5-HT1 receptor caused tetrodotoxin (TTX)-insensitive relaxations in the preparations from 3 regions. Stimulation of the 5-HT2 receptor caused TTX-insensitive contractions in the preparations of fundus and antrum. Stimulation of 5-HT3 receptors caused contractions that were sensitive to TTX and atropine and enhanced the outflow of [3H]ACh from preparations of only antrum. Stimulation of 5-HT4 receptors caused contractions of antral strips and decreased relaxations of corporal strips and enhanced the outflow of [3H]ACh from the preparations of both corpus and antrum. In the guinea pig stomach, the fundus possesses relaxant 5-HT1 receptor < contractile 5-HT2 receptors and caused the contractile response to 5-HT. The corpus possesses relaxant 5-HT1 receptors and relaxant receptors other than 5-HT1, 5-HT2, 5-HT3 and 5-HT4 receptors > contractile 5-HT4 receptor, and therefore 5-HT caused relaxations. The antrum possesses relaxant 5-HT1 receptor < contractile 5-HT2, 5-HT3 and 5-HT4 receptors, and thus 5-HT caused contractions.

Animals↗
PubMed1999

Ability of mosapride to bind to 5-HT4 receptor in the human stomach.

Ability of mosapride, a gastrokinetic agent, to bind to 5-HT4 receptor was examined in the stomach of human and guinea pig by in vitro receptor autoradiography. [125I]SB207710 binding sites were detected in the muscle layer including the myenteric plexus of the stomach from both humans and guinea pigs, although the binding was observed more clearly and densely in the stomach of guinea pigs than humans. Mosapride as well as SB204070 inhibited the binding of [125I]SB207710. Thus, mosapride possesses the ability to bind to 5-HT4 receptors of human stomach and may modulate the motility, as in the case of guinea pig stomach.

Aged↗
PubMed1999

Genetic analysis of a dentatorubral-pallidoluysian atrophy family: relevance to apparent sporadic cases.

Dentatorubral-pallidoluysian atrophy (DRPLA) is associated with an unstable CAG trinucleotide sequence. We describe a DRPLA family whose members have an allele containing an expanded CAG repeat, even in an elderly neurologically normal individual. The proband developed DRPLA at age 14. She was initially considered a sporadic case, but later her sister became symptomatic. Investigation of the number of CAG repeat units in her family revealed the 81-year-old father to have an expanded CAG repeat of 51 units. To our knowledge, such an advanced aged unaffected patient has not been previously documented. The present example may explain apparent sporadic cases.

Adult↗
PubMed1999

Technology to obtain sustained release characteristics of drugs after delivered to the colon.

To determine the necessary technology by which sustained drug release is obtained after drug is delivered to the colon, two kinds of microcapsules were prepared and were filled in a pressure-controlled colon delivery capsule (PCDC). As a model drug 5-aminosalicylic acid (5-ASA) was used, because the target site of 5-ASA is the entire large intestine. 5-ASA was microencapsulated using a water-insoluble polymer, ethylcellulose (EC) or with pH-sensitive polymers, Eudragit L-100 or S-100 and encased in PCDC. The particle size of these microcapsules was around 800 microns and the loading efficiencies of 5-ASA were approximately 90%. In vitro dissolution tests were performed with the prepared microcapsules. The release rate of 5-ASA from the microcapsules was significantly prolonged as compared to 5-ASA powder, although there were no significant differences in the release rates between these microcapsules. By incorporating the 5-ASA microcapsules into PCDC, sustained release PCDCs for colon delivery were prepared and in vivo evaluation was performed using beagle dogs. As a fast release colon delivery system, PCDCs were prepared with 5-ASA powder suspended in suppository base. After oral administration of the test preparations to beagle dogs, plasma 5-ASA concentrations were measured and sustained release characteristics of 5-ASA from the test preparations were evaluated from the plasma 5-ASA concentration-time profiles. The first appearance time of 5-ASA into the systemic circulation after oral administration were 3 h for all the colon delivery preparations and it was thought that these test preparations were delivered to the colon. Both EC microcapsules and Eudragit S-100/RS-100 microcapsules in PCDC showed longer the mean residence time MRT, 8.2 +/- 0.6 h and 8.7 +/- 0.9 h, than Eudragit L-100/RS-100 microcapsules in PCDC where the MRT was 6.6 +/- 0.2 h. Since PCDCs containing 5-ASA powder exhibited a MRT of 7.0 +/- 1.0 h, these two types of preparations have suggested sustained release characteristics.

Algorithms↗
PubMed1999

Preparation and evaluation of once-a-day injectable microspheres of interferon alpha in rats.

Gelatin microspheres (ms) and gelatin/BSA (bovine serum albumin) or gelatin/alginate ms were prepared by encapsulating fluorescein isothiocyanate (FITC) labeled dextran or interferon alpha (IFN-alpha). Ms were obtained by an emulsion-solvent-extraction method. Gelatin and gelatin/BSA ms were obtained by treating water-in-oil (W/O) emulsions with iso-propyl alcohol. Gelatin/alginate ms having different composition (25/1, 20/1, 15/1, 10/1 and 5/1) were obtained by treating a W/O emulsion composed of gelatin and sodium alginate with 0.5 M calcium chloride solution. The average diameters of all the prepared ms were approximately 300 microns. The FITC-dextran loading efficiencies were 96.5 +/- 0.6% for gelatin ms (#1), 97.3 +/- 2.2% for gelatin/BSA ms (#2) and 68.7 +/- 2.2%, 55.0 +/- 3.9%, 47.5 +/- 3.3%, 44.4 +/- 1.2%, 27.1 +/- 2.2% for gelatin/alginate ms (#3-#7). The IFN-alpha loading efficiencies were 10.8 +/- 0.5% for gelatin/BSA ms (#8) and 22.5 +/- 1.8%, 17.6 +/- 0.9% and 14.5 +/- 0.5% for gelatin/alginate ms (#9, #10 and #11). In vitro release studies with ms containing FITC-dextran showed that the release rate of FITC-dextran from the ms decreased by the modification of gelatin ms with BSA or sodium alginate, although the effect of BSA addition to gelatin ms did not elucidate satisfactory sustained-release characteristics of FITC-dextran after subcutaneous (s.c.) injection to rats. By decreasing the formulated ratio of gelatin/alginate from 25/1 to 5/1, the mean T50%, the time when the half amount of FITC-dextran contained was released from the ms, increased from 1.7 +/- 0.1 to 13.8 +/- 3.6 h and three ms preparations (#4, #5 and #6) showed sustained-release characteristics on the serum FITC-dextran concentration-time profiles. Based on these results, three types of ms containing IFN-alpha were prepared and in vivo pharmacokinetic studies were performed in rats, where the dose of IFN-alpha was 2 x 10(4) IU/rat. By the addition of alginate to gelatin, the release rate of IFN-alpha was decreased and the serum IFN-alpha concentration-time profiles showed better sustained-release characteristics of IFN-alpha from #10 ms than the other IFN-alpha ms (#8, #9 and #11) after s.c. injection to rats.

Alginates↗
PubMed1999

Characterization of norfloxacine release from tablet coated with a new pH-sensitive polymer, P-4135F.

A new pH-sensitive polymer, P-4135F, was evaluated as a colon delivery device for norfloxacine (NFLX) which is used for the therapy of patients with Vero toxin-producing Escherichia coli gastroenteritis. P-4135F has a dissolution threshold pH of 7.2 which is higher than the conventional pH-sensitive polymers, Eudragit S100 and L100. To compare the dissolution site of P-4135F coated tablets with other enteric polymer coatings, mini-tablets containing sodium fluorescein (FL) as a model drug were prepared by coating them with the three polymers. After oral administration of FL mini-tablets to rats, the first-appearance time, Ti, of FL into the systemic circulation was measured. The Tis were 0.7+/-0.2 h for Eudragit L100, 1.8+/-0.4 h for S100 and 2.0+/-0.3 h for P-4135F. Direct inspection of the dissolution process of the FL mini-tablets after oral administration to rats was performed by abdominal incision studies. All of the coated FL mini-tablets started to dissolve in the rat ileum. The dissolution sites were identified to be proximal to the ileocecal junction for P-4135F, at the middle part of the ileum for Eudragit S100 and at the proximal part of the ileum for Eudragit L100. NFLX tablets with different membrane thicknesses of P-4135F were prepared and were orally administered to beagle dogs. The colon delivery efficiency was evaluated by measuring the Ti of NFLX into the systemic circulation. The mean Tis were 1.33+/-0.33 h for 56.8+/-0.5 microm membranes, 3.75+/-0.25 h for 64.6+/-0.7 microm membranes, 4.00+/-1.00 h for 70.5+/-0.5 microm membranes and 3.00+/-1.00 h for 74.9+/-0.4 microm membranes. By comparing the Ti, 4.33+/-0.33 h, obtained after oral administration of NFLX in a pressure-controlled colon delivery capsule, and the colon arrival time, 3.5+/-0.3 h, determined by a sulfasalazine test in beagle dogs. P-4135F coated NFLX tablets appeared to dissolve and disintegrate before reaching the colon. Studies using rats and beagle dogs have suggested that P-4135F dissolves in the lower part of the small intestine, i.e., the ileum. These studies also suggest that this new polymer will be useful for the delivery of NFLX to the lower part of the small intestine.

Acrylic Resins↗
PubMed1999

[Alterations in neurotransmitter, amino acid and free radical related substances in cerebrospinal fluid in patients with cerebrovascular diseases].

Acetylcholinesterase (AChE), choline, monoamine and its metabolite, amino acid and superoxide dismutase (SOD) levels were measured in cerebrospinal fluid (CSF) in patients with cerebrovascular diseases. Patients were classified into the following four groups; controls: normal subjects without neurological disease, group A: cerebral hemorrhage, group B: cerebral infarction, group C: patients with mental impairment, including those in groups A and B, and a low score on Hasegawa's Dementia Rating Scale. CSF AChE level of groups A, B and C was decreased significantly, while choline concentration from patients showed a increase compared with that of control cases. CSF alanine concentration showed a tendency to increase, while glycine and glutamate tended to decrease. CSF epinephrine, norepinephrine or 3-methoxy-4-hydroxyphenylethylen glycol concentrations of groups A, B and C did not exhibit a significant difference from that in control cases. Some cases with cerebrovascular diseases showed low concentrations of both CSF 5-hydroxyindole acetic acid and homovanillic acid. However, dihydroxyphenyl acetic acid concentration was higher than in control cases. The CSF SOD level was not significantly from that in control cases. The changes in neurochemical substances in the CSF support their use as markers of cerebrovascular disease-related change.

Acetylcholinesterase↗
PubMed1999

Calpain inhibitor causes accumulation of ubiquitinated P-glycoprotein at the cell surface: possible role of calpain in P-glycoprotein turnover.

P-glycoprotein (Pgp) is a plasma-membrane glycoprotein that confers multi-drug resistance (MDR) on cells and displays ATP-driven drug pumping. The possible contribution of calpain-mediated proteolytic pathways to the functional regulation of the Pgp molecule was evaluated using K562/DXR, MDR cells. N-Acetyl-L-leucyl-L-leucyl-norleucinal was effluxed by Pgp, but N-benzyloxycarbonyl-L-leucyl-L-leucinal (zLLal), an inhibitor of calpain, retarded the degradation of Pgp leading to accumulation of the molecule largely at the cell surface membrane. Treatment with brefeldin A did not obstruct the zLLal-induced Pgp accumulation. NH4Cl increased the cytoplasmic Pgp level, with a slight to significant decrease at the cell surface membrane. Ubiquitin-ELISA and western blot analysis confirmed that the Pgp molecule, which accumulated mainly at the cell surface, was ubiquitinated. However, lactacystin did not show any accumulation of Pgp in either the cytoplasm or the cell surface membrane, suggesting that the proteasome did not participate in the phenomenon. Additionally, the Pgp was limitedly proteolyzed by calpain into two 98 kDa and 69 kDa, fragments within one minute. Despite the increased accumulation of Pgp at the cell surface after treatment with calpain inhibitor, the cytoplasmic doxorubicin level of the cells treated with a calpain inhibitor was higher than that of non-treated cells and approached that of parental cells. These results indicated that calpain involved Pgp turnover and that calpain inhibition induced ubiquitinated Pgp-accumulation mainly at the cell surface membrane with a reduction in its own functions suggesting that the modulation of Pgp-turnover involves MDR-reversal by another approach.

ATP Binding Cassette Transporter, Subfamily B↗
PubMed1999

[Non-invasive continuous hemodynamic measurement during operation for a child with coarctation of aorta].

For non-invasive hemodynamic monitoring, DYNEMO 3000 (SOMETEC Inc) has a 10 mHz ultrasonic echo scan and a 5 mHz Doppler velocimeter connected to an echo-oesophageal probe allowing continuous measurement of the aortic diameter and of the blood flow velocity in the descending aorta. This device thus can only measure the aortic blood flow, but also calculate the stroke volume and the systemic vascular resistance. Moreover, the systolic time intervals and the length of the pre-ejection period can be measured with the oscillometric tensiometer and the electrocardiography. This paper describes a case in which this device was used for a child with coarctation of the aorta. The hemodynamic changes were measured continuously during coarctectomy. During the temporary bypass, the aortic blood flow and the stroke volume decreased, but on the other hand, the total vascular resistance increased at the same time. After the bypass, these parameters returned to the values before the bypass. We think that this device is useful as a non-invasive monitor to observe the hemodynamic changes continuously during operation for a child with congenital heart disease.

Adolescent↗